A video coding system may be used to compress digital video signals to reduce the storage need and/or transmission bandwidth. A video coding system may include a block-based system, a wavelet-based system, an object-based system, or the like. Block-based hybrid video coding systems may be used and deployed. Examples of block-based video coding systems include, but are not limited to international video coding standards such as the MPEG1/2/4 part 2, H.264/MPEG-4 part 10 AVC and VC-1 standards.
With the growth of smart phones and tablets both in resolution and computation capability, additional video applications, such as video chat, mobile video recording and sharing, and video streaming, may require video transmission in heterogeneous environments. Heterogeneity may exist on the client and/or on the network. On the client side, the spatial resolution of the display of a client device may increase (e.g., smart phone, tablet, TV, or the like). On the network side, video may be transmitted across the Internet, WiFi networks, mobile (e.g., 3G, 4G, or the like) networks, and/or any combination thereof.
To improve the user experience and video quality of service, scalable video coding may be utilized. Scalable video coding may encode the signal once at the highest resolution and enable decoding from subsets of the streams depending on the specific rate and resolution used by an application and/or supported by a client device. The term resolution may refer to a number of video parameters, such as but not limited to, spatial resolution (e.g., picture size), temporal resolution (e.g., frame rate), and/or video quality (e.g., subjective quality such as MOS, and/or objective quality such as, but not limited to PSNR, SSIM, or VQM). Other video parameters may include chroma format (e.g., YUV420, YUV422, or YUV444), bit-depth (e.g., 8-bit video, 10-bit video, or the like), complexity, view, gamut, and aspect ratio (e.g., 16:9, 4:3, or the like). A video codec (e.g., a scalable extension of HEVC) may support spatial scalability (e.g., the scalable bitstream may include signals at more than one spatial resolution), quality scalability (e.g., the scalable bitstream may include signals at more than one quality level), and/or view scalability (e.g., the scalable bitstream may include 2D and 3D video signals).